Two days before a Georgia dad allegedly left his 22-month-old son in an SUV for seven sweltering hours, a father in Florida was accused of forgetting his 9-month-old daughter in the backseat of his pickup.

Another 30 percent of cases had no charges filed, while in the remaining 10 percent, it was unclear what happened.

“There isn’t any rhyme or reason to why it varies from state to state,” said Amber Rollins, a director with KidsAndCars.org, a nonprofit child-safety group. “Even case by case, you never know what’s going to happen.”

Of those arrested and charged in a child’s death, the majority — 60 percent — were ultimately convicted of a crime, such as child abuse, child neglect or negligent homicide.

In May 2013, Texas woman Vibha Marks was charged with second-degree felony child abandonment after she left her 1-year-old daughter in a hot car, reported NBC Dallas-Fort Worth. Marks, a teacher, later said she thought she had dropped the girl off at day care before going to work.

A grand jury ultimately declined to indict Marks.

“Sadly, this isn’t the first case and we do see these, particularly during the summer months.”

Marks’ claim that she simply forgot her daughter — while some might consider it unfathomable — is a common refrain heard in these cases, Rollins said.

“They’re out of sight, and now they’re also riding in rear-facing car seats up until age 2,” Rollins said. “That car seat looks the same whether the baby is in there or not.”

Incidents of children being left in the back seat of cars spiked in the mid-1990s, as states began requiring children to ride in backseats to avoid deployed air bags, the KidsAndCars.org data show.

Rollins added that parents of young children can be under a new kind of stress that leaves their brains distracted — or on autopilot.

Lillie, the 31-year-old Florida dad who forgot his 9-month-old in his pickup, told officers there was a disruption in his routine that morning when he should have dropped the girl at day care, according to Florida Today.

“Mentally, I think he sort of got ahead of himself. He had it in his mind that he had already dropped the child off,” said Rockledge, Florida, police Lt. Donna Seyferth, according to NBC affiliate WESH.

“Sadly, this isn’t the first case and we do see these, particularly during the summer months,” she added.

Cars can quickly become death traps for children during the summer. When temperatures outdoors hit 90 degrees Fahrenheit, the inside of a car can feel like 109 degrees in just 10 minutes — and 138 degrees in 90 minutes, according to San Francisco State University research.

Police were still investigating the death of Lillie’s daughter Thursday, and had not determined whether they plan to file charges.

In a 911 call, Lillie told a dispatcher his girl was “in the car for hours. I absolutely forgot about her. She’s not alive.”